This is something I'm currently struggling with. I rent a house and the roof is leaking in two different rooms. Problem is that last time I had the landlord do any repairs he increased my rent by $300 a month. I know that having a leaky roof is damaging his property, but it's only a minor inconvenience for me at the moment.
I'm not about to spend an extra $6,000+ a year just to preserve his property when I can keep it from bothering me with a tack, some string, and a pitcher for the water to go into.